Озвучка текста с помощью API yandex speechkit

speechkit.php

#!/usr/bin/env php
<?php
/**
 * Using
 * ~$ php speechkit.php book.txt
 * 
 * @see https://tech.yandex.ru/speechkit/cloud/doc/guide/concepts/tts-http-request-docpage/
 */

$apiUrl = 'https://tts.voicetech.yandex.net/generate';
$options = [
    'key' => '1e58cabf-fa4a-45df-b461-174f331d44ff',
    'speaker' => 'oksana',
    'format' => 'mp3',
    'lang' => 'ru-RU',
    'speed' => 1.2
];

$max_text_size = 2000;

if (empty($argv[1])) {
    echo "Первым параметром должен быть путь к txt файлу\n";
    exit(1);
}

$book = $argv[1];
$path_parts = pathinfo($book);
$out_file_name = $path_parts['dirname'] . '/' . $path_parts['filename'] . '.' . $options['format'];

$out_handler = fopen($out_file_name, 'a+');
fseek($out_handler, -1, SEEK_END);

$handle = fopen($book, 'r');

$i = 0;
$text = null;

while (($buffer = fgets($handle)) !== false) {
    $i++;

    $buffer = trim($buffer);
    if (empty($buffer)) {
        continue;
    }
    if (preg_match('~[\d\w]+~u', $buffer) === 0) {
        continue;
    }

    if ((strlen($text) + strlen($buffer)) < $max_text_size) {
        $text .= ' ' . $buffer;
        continue;
    }

    echo "\rline: {$i}\tsize: " . strlen($text) . "\t";
    $options['text'] = $text;
    $text = $buffer;

    $url = $apiUrl . '?' . http_build_query($options);
    $data = @file_get_contents($url);

    if (!$data) {
        break;
    }

    fwrite($out_handler, $data);
}

if ($text) {
    $options['text'] = $text;
    $url = $apiUrl . '?' . http_build_query($options);
    $data = @file_get_contents($url);
    fwrite($out_handler, $data);
}

echo "\n";

fclose($out_handler);
fclose($handle);